An examination of verbal working memory capacity in children with specific language impairment.

This study investigated verbal working memory capacity in children with specific language impairment (SLI). The task employed in this study was the Competing Language Processing Task (CLPT) developed by Gaulin and Campbell (1994). A total of 40 school-age children participated in this investigation, including 20 with SLI and 20 normal language (NL) age-matched controls. Results indicated that the SLI and NL groups performed similarly in terms of true/false comprehension items, but that the children with SLI evidenced significantly poorer word recall than the NL controls, even when differences in nonverbal cognitive scores were statistically controlled. Distinct patterns of word-recall errors were observed for the SLI and NL groups, as well as different patterns of associations between CLPT word recall and performance on nonverbal cognitive and language measures. The findings are interpreted within the framework of a limited-capacity model of language processing.     

Verbal working memory and sentence comprehension in children with specific language impairment.

In this study we examined the influence of verbal working memory on sentence comprehension in children with SLI. Twelve children with SLI, 12 normally developing children matched for age (CA), and 12 children matched for receptive vocabulary (VM) completed two tasks. In the verbal working memory task, children recalled as many real words as possible under three processing load conditions (i.e., no-load condition; single-load condition, where words were recalled according to physical size of word referents; and dual-load condition, where words were recalled by semantic category and physical size of word referents). In the sentence comprehension task, children listened to linguistically nonredundant (shorter) and linguistically redundant (longer) sentences. Results of the memory task showed that the children with SLI recalled fewer words in the dual-load condition than their CA peers, who showed no condition effect. The SLI and VM groups performed similarly overall, but both groups showed poorer recall in the dual-load condition than in the other conditions. On the sentence comprehension task, children with SLI comprehended fewer sentences of both types than the CA children and fewer redundant sentences relative to themselves and to the VM children. Results were interpreted to suggest that children with SLI (a) have less functional verbal working memory capacity (i.e., ability to coordinate both storage and processing functions) than their CA peers and (b) have greater difficulty managing both their working memory abilities and general processing resources than both age peers and younger children when performing a "complex" off-line sentence processing task.     

Complex sentence comprehension and working memory in children with specific language impairment

PURPOSE: This study investigated the association of 2 mechanisms of working memory (phonological short-term memory [PSTM], attentional resource capacity/allocation) with the sentence comprehension of school-age children with specific language impairment (SLI) and 2 groups of control children. METHOD: Twenty-four children with SLI, 18 age-matched (CA) children, and 16 language- and memory-matched (LMM) children completed a nonword repetition task (PSTM), the competing language processing task (CLPT; resource capacity/allocation), and a sentence comprehension task comprising complex and simple sentences. RESULTS: (1) The SLI group performed worse than the CA group on each memory task; (2) all 3 groups showed comparable simple sentence comprehension, but for complex sentences, the SLI and LMM groups performed worse than the CA group; (3) for the SLI group, (a) CLPT correlated with complex sentence comprehension, and (b) nonword repetition correlated with simple sentence comprehension; (4) for CA children, neither memory variable correlated with either sentence type; and (5) for LMM children, only CLPT correlated with complex sentences. CONCLUSIONS: Comprehension of both complex and simple grammar by school-age children with SLI is a mentally demanding activity, requiring significant working memory resources.     

Phonological working memory in Spanish-English bilingual children with and without specific language impairment

We examined the performance of sequential bilingual children with and without Specific Language Impairment (SLI), who had Spanish as an L1 and English as their L2, on an auditory non-word repetition task using Spanish phonotactic patterns. We also analyzed the accuracy with which this task distinguished these children (according to children's and mothers' performance). Eleven Hispanic children with SLI (M=8;10), 11 age-matched children with Typical Language Development (TLD, M=9;1), and 12 mothers, participated. They were living in New York City. The participants' repetition of 20 non-words (four at each of five syllable lengths) was scored for item and segmental accuracy, and error type. We examined the relations among children's non-word repetition performance, language scores, and, for a subset of the children, their mothers' non-word repetition performance. The percentage of correct non-words was significantly lower in children with SLI than in children with TLD. A length effect was found in 3-4-5 syllable non-words. Consonant substitutions and consonant omissions were significantly higher in children with SLI than with TLD. Both groups showed a similar relative pattern of more consonant than vowel errors. The children's non-word repetition performance correlated strongly with three of the four Spanish ITPA subtests we administered. The mothers of children with SLI performed more poorly than the mothers of the children with TLD, for the 20 non-words and the subset of 3-4-5 syllable non-words. Non-word repetition performance is an accurate identifier of language status in these groups (likelihood ratios are reported). The potential clinical application of this task in identifying SLI in bilingual Spanish-speaking children (on the basis of children's and mothers' performance) is discussed. LEARNING OUTCOMES: In the future, with a set of norms, this task could be used as a screening test to help detecting children with SLI or at risk for SLI.     

Visuospatial immediate memory in specific language impairment.

PURPOSE: Investigations of the cognitive processes underlying specific language impairment (SLI) have implicated deficits in verbal short-term and working memory and in particular the storage and processing of phonological information. This study investigated short-term and working memory for visuospatial material for a group of children with SLI, to test whether the verbal memory impairments already established extend to the visuospatial domain. METHOD: Fifteen children with SLI and control groups of children matched on chronological age and language age completed tests of visuospatial short-term and working memory. RESULTS: The SLI group performed comparably with age-matched control children on all measures and at a higher level than the language-age control group on several measures. CONCLUSIONS: The visuospatial short-term and working memory abilities were at age-appropriate levels in this SLI group. This contrasts markedly with their impairments on tests of verbal short-term and working memory.     

A comparison of language abilities in adolescents with Down syndrome and children with specific language impairment.

This article compared the language profiles of adolescents with Down syndrome (DS) and children with specific language impairment matched for nonverbal cognitive ability, and investigated whether similar relationships could be established between language measures and other capacities in both groups. Language profiles were very similar: Expressive language was more affected than language comprehension, and grammar was more affected than vocabulary in both domains. Both groups were impaired on tests of grammatical morphology and phonological memory. There were some differences between the groups, but these could be attributed to other features of development of people with DS.     

Working memory capacity and language processes in children with specific language impairment.

This study examined the interaction between working memory and language comprehension in children with specific language impairment (SLI), focusing on the function of the central executive component and its interaction with the phonological loop (A. D. Baddeley, 1986) in complex working memory tasks. Thirteen children with SLI and 13 age-matched (age range = 7;0 [years;months] to 10;0) children with typical language development participated. The tasks combined traditional nonword repetition tests and sentence comprehension by using sentences that differed in length and syntactic complexity. The children with SLI exhibited larger processing and attentional capacity limitations than their age-matched peers. Increased word length and syntactic complexity resulted in a large performance decrease in nonword repetition in both groups. There were some variations in the error pattern, which may indicate qualitative differences between the 2 groups. The performance of the children with SLI in nonword repetition, across the different tasks, indicated a limitation in simultaneous processing rather than difficulty in encoding and analyzing the phonological structure of the nonwords. Furthermore, syntactic complexity had a greater effect on performance accuracy than did sentence length.     

A preliminary investigation of reduplication in children with specific language impairment

The frequency of reduplication was examined in relation to syllable maintenance, final consonant production, and whole word repetitions in two preschool children with specific language impairment--one who reduplicated frequently and one who did so infrequently. Spontaneous speech was sampled for a period of 18 months. During the single-word utterance period, reduplication was associated with infrequent production of final consonants but frequent maintenance of multisyllabic structure. After the single-word utterance period the child who had frequently reduplicated during this period ceased reduplication but frequently produced whole word repetitions. Infrequent production of final consonants continued, but syllable maintenance decreased. The data are discussed in relation to hypotheses about the function of reduplication and the function of whole word repetitions in language development.     

The strengths and weaknesses in verbal short-term memory and visual working memory in children with hearing impairment and additional language learning difficulties

Objectives

To compare verbal short-term memory and visual working memory abilities of six children with congenital hearing-impairment identified as having significant language learning difficulties with normative data from typically hearing children using standardized memory assessments.

Methods

Six children with hearing loss aged 8–15 years were assessed on measures of verbal short-term memory (Non-word and word recall) and visual working memory annually over a two year period. All children had cognitive abilities within normal limits and used spoken language as the primary mode of communication. The language assessment scores at the beginning of the study revealed that all six participants exhibited delays of two years or more on standardized assessments of receptive and expressive vocabulary and spoken language.

Results

The children with hearing-impairment scores were significantly higher on the non-word recall task than the “real” word recall task. They also exhibited significantly higher scores on visual working memory than those of the age-matched sample from the standardized memory assessment.

Conclusions

Each of the six participants in this study displayed the same pattern of strengths and weaknesses in verbal short-term memory and visual working memory despite their very different chronological ages. The children’s poor ability to recall single syllable words in relation to non-words is a clinical indicator of their difficulties in verbal short-term memory. However, the children with hearing-impairment do not display generalized processing difficulties and indeed demonstrate strengths in visual working memory. The poor ability to recall words, in combination with difficulties with early word learning may be indicators of children with hearing-impairment who will struggle to develop spoken language equal to that of their normally hearing peers. This early identification has the potential to allow for target specific intervention that may remediate their difficulties.     

Speed of processing, working memory, and language impairment in children.

PURPOSE: Children with language impairment (LI) often perform below the level of typically developing peers on measures of both processing speed and working memory. This study examined the relationship between these 2 types of measures and attempted to determine whether such measures can account for the LI itself. METHOD: Fourteen-year-old children with LI and their typically developing peers participated in a wide range of processing speed and working memory tasks and were administered a comprehensive language test battery. Confirmatory factor analyses were used to compare 3 nested models designed to examine the dimensionality of the speed and working memory measures. A model that included a general speed factor was also evaluated. RESULTS: The models meeting our evaluation criteria treated speed and working memory as separable factors. Furthermore, nonverbal as well as verbal processing factors emerged from these analyses. Latent variable regression analyses showed that each of the appropriate models accounted for 62% of the variance in the children's concurrent composite language test scores, with verbal working memory making the largest contribution. CONCLUSIONS: These findings shed light on the relationship among different types of processing and suggest that processing factors can contribute to the understanding of language disorders.     

Self-esteem in children with specific language impairment.

The purpose of this preliminary study was to probe the self-perceptions of a group of children with specific language impairment (SLI) and their typically developing peers. A measure of self-esteem was administered to 46 children between the ages of 6 and 9 years old and 34 children between the ages 10 and 13. In the younger group, there were no statistically significant differences between children with SLI and typically developing children in the way they perceived themselves across domains of competence and acceptance. In the older group, children with SLI perceived themselves more negatively in scholastic competence, social acceptance, and behavioral conduct than did children with typical language development. Differences were evident in areas that were most affected by language impairment.     

Declarative and procedural memory in Danish speaking children with specific language impairment

It has been proposed that the language problems in specific language impairment (SLI) arise from basal ganglia abnormalities that lead to impairments with procedural and working memory but not declarative memory. In SLI, this profile of memory functioning has been hypothesized to underlie grammatical impairment but leave lexical knowledge relatively unaffected. The current study examined memory and language functioning in 13 Danish-speaking children with SLI and 20 typically developing (TD) children. Participants were administered tasks assessing declarative, procedural and verbal working memory as well as knowledge of past tense and vocabulary. The SLI group performed significantly poorer than the TD group on the measure of verbal working memory. Non-significant differences between groups were observed on the measure of declarative memory, after controlling for verbal working memory. The groups were found to perform at comparable levels on the procedural memory task. On the language measures, the SLI group performed significantly poorer than the TD group on the past tense and vocabulary tasks. However, the magnitude of the difference was larger on the task assessing past tense. These results indicate grammatical knowledge is relatively more affected than lexical knowledge in Danish speaking children with SLI. However, the results were not consistent with the proposal linking impaired grammar to impairments with procedural memory. At the same time, the study does not rule out that other aspects of procedural learning and memory contribute to the language problems in SLI. Learning outcomes: The reader will be introduced to (1) different memory systems, in particular the declarative, procedural and working memory systems and (2) also research examining the relationship between these different memory systems and language in children with SLI.     

Health-related quality of life of adolescents with childhood diagnosis of specific language impairment

Objective

To evaluate the health-related quality of life (HRQoL) of adolescents with a diagnosis of specific language impairment (SLI).

Methods

A clinical sample of 67 subjects with a childhood diagnosis of SLI, now aged 12-16, were asked to fill out the generic 16D HRQoL questionnaire. The comparison group comprised 235 typically developing peers. Another questionnaire gathered information about school and rehabilitation.

Results

Of the surveyed 73% answered; 77% were male. Total HRQoL score between subjects and controls did not differ. The group profiles had some differences. The SLI group experienced more problems in the dimension of mental functioning (p = 0.001), whereas the control group was worse off on the dimension vitality (p = 0.003). In the SLI group, low vitality was related to low verbal IQ in childhood, and own perception of literacy problems. Long-term speech therapy was associated with problems in the dimension of speech.

Conclusions

The overall HRQoL of adolescents with SLI was at age-level, but language-related problems seemed to lead to increased problems in mental functioning. Low vitality was more of a problem for the controls, but also for those SLI children who had inferior language performance. Adolescents’ own perceptions of their life quality are of clinical importance, and 16D seems a usable tool to capture them.     

Familial aggregation in specific language impairment.

A case-control family study design, in which the current language-related abilities of all biological, primary relatives (mother, father, siblings) of probands with specific language impairment (SLI) and matched controls were assessed, was used to investigate familial aggregation for language disorders. Current test data from each family member showed the rate of language impairment for mothers, fathers, sisters, and brothers of the SLI probands to be significantly higher than for members of control families. Impairment rates for fathers and mothers were approximately equal, whereas rates for brothers were significantly higher than for sisters. In SLI proband families, Language Impairment (LI) occurred in 13.0% of offspring (excluding proband) with neither parent affected, 40% of offspring with one parent affected, and 71.4% of offspring in families in which both parents were language impaired. Rates of impairment as determined in current testing were compared directly to impairment rates estimated from family-history questionnaires collected from the same families. Group data showed impairment rates estimated from the family-history questionnaires to be similar to the rates based on actual testing. Furthermore, both appeared in line with rates based primarily on questionnaire data as reported previously in the literature. However, case-by-case analyses showed poor intrasubject agreement on classification as language impaired on the basis of current testing as compared to history information.     

Speed of processing in children with specific language impairment.

The aim of the present study was to investigate the speed with which children with specific language impairment (SLI) respond on a range of tasks. Seventy-seven third-grade children participated in 10 different tasks (involving a total of 41 conditions), including nonlinguistic and linguistic activities. Mean response times (RTs) of children with SLI (n = 29) increased as a function of mean RTs of children with normal language (NLD, n = 29) under each of three different regression models; children with SLI responded more slowly across all task conditions, and also when linguistic and nonlinguistic tasks were analyzed separately. Children with nonspecific language impairment (NLI) were also included (n = 19). The results were similar to those for children with SLI, but the degree of slowing was greater. The results of the group analyses support the hypothesis that speed of processing in children with SLI is generally slower than that of children with normal language. However, some children with SLI do not appear to show deficits of this type.     

Naming errors of children with specific language impairment.

This paper explores why children with SLI are less accurate than peers in naming pictures. Subjects included 66 children with SLI (aged 4:3 to 9:7) with 2 subgroups, one with expressive-only language deficits (SLIexp) and one with receptive and expressive language deficits (SLImix), and 66 children with no language impairment (NLI). Children with SLI made more errors than children with NLI, and proportionally more of their errors were names of objects associated with the pictured object (e.g., shoe/foot) and names that were phonologically related to the target than were those with NLI. The relative frequency of error types was related to pattern of language deficit; in comparison to their NLI peers, a greater proportion of SLIexp errors were phonological errors, and a greater proportion of the SLImix errors were semantic associated, semantic perceptual, and nonsemantic perseverative. The proportion of semantic-associated errors also discriminated a subgroup of the children with SLI from a matched subgroup of the children with SLImix. Interpretations and potential implications are discussed.     

Arithmetic calculation, short-term memory, and language performance in children with specific language impairment: a 5-year follow-up.

A 5-year follow-up of the arithmetic calculation abilities of low-income children with specific language impairment (SLI) is reported. The performance of fourth- and fifth-grade children with SLI was compared with that of typically developing low-income peers and with younger, typically developing low-income children. Short-term memory, language, and arithmetic calculation abilities were assessed. Compared to their age-matched peers, the SLI group exhibited low scores on a number recall task, a marked difficulty with mathematical calculation under timed conditions, and numerous errors when retrieving rote math facts such as 7 x 6 =. Although children with SLI made more written calculation errors than their age-matched peers, they did not differ in the type of errors made. However, strategies used to solve written calculation differed among the groups. Rather than use automatic math fact retrieval, children with SLI were more likely to use counting strategies to solve calculation problems. These findings offer further evidence that children with SLI have difficulty with rote memory. The findings also document the real-world consequences of slow, inefficient memory retrieval in children with SLI.     

The comprehension of wh-questions in children with specific language impairment.

Current theories of specific language impairment (SLI) in children fall into 2 general classes: those that attribute SLI to processing limitations and those that attribute the disorder to deficits in grammatical knowledge. In this study, the authors examined children's comprehension of subject and object Wh-questions because they offer the means of determining the relative contribution to performance of knowledge and of processing. Comprehension of subject and object Wh-questions presumably requires knowledge of grammatical movement. However, through manipulation of the length of the questions, it is also possible to vary the processing demands of the questions. If a simple deficit in knowledge of movement is involved, children should show poorer comprehension on object questions than on subject questions, regardless of sentence length. However, if processing limitations are involved, length should affect comprehension of object questions but not subject questions. Children with SLI and typically developing (TD) children matched on receptive vocabulary test scores participated in a comprehension task consisting of short and long subject and object Wh-questions. The two groups performed similarly on short questions, each showing high accuracy in both subject and object conditions. However, the children with SLI showed poorer performance on long object questions compared to long subject questions. They were also less accurate on long object questions than were children in the TD group. We argue that demands on linguistic processing abilities play an important role in the difficulties experienced by children with SLI.